Strategies to achieve sustainable and Durable Concrete ...saudiconcreteconference.com/pdfs/Dr. Emad Abu Aisheh -Stratrgies to... · Strategies to achieve sustainable and Durable Concrete

Saudi Aramco: Company General Use

Dr. Emad Abu-Aisheh, Engineering Specialist

Saudi Aramco

Consulting Services Department

Strategies to achieve sustainable and Durable

Concrete with Case Studies

SAUDI CONCRETE CONFERENCE – MAY 1 - 4, 2016

FIRST SAUDI CONCRETE CONFERENCE May 2016


1 Introduction

2 Definitions

3 Modes of Degradation of reinforced concrete

Content

5

4Provisions to enhance sustainability through durability

of concrete structures

Conclusions



1 Introduction

2

3

Content

5

4



Introduction

FACTS: “The bottom line”

• At present, an average of 5 percent of global greenhouse gases emitted worldwide result from the manufacture of cement, with nearly one tone of CO2

being emitted for every tone of cement produced

• More than half (60%) of the CO2 emitted during cement production is due to calcination, a chemical reaction from heating limestone.



Besides water, concrete is the most commonly used material on earth.

Each year, approximately four metric tons of concrete are used for every one of the nearly seven billion people on our planet. (USGS 2009)

• 28 billion ton of concrete

• 3.6 billion ton of cement (14%)

• 2.4 billion ton of water (9%)

• 22 billion ton of aggregate (77%)

Consequences of producing 3.6 billion tons of Cement

• Generates 3.6 billion ton of CO2

• Responsible for 5% CO2 world

production

Introduction


Problem!


The mix in ready mixed concrete

Introduction

Evolution on CO2 release per kg of cement

produced in different regions



CO2 emissions per country

from fossil-fuel use and

cement production

Source: EDGAR 4.3 FT2014 (JRC/PBL, 2015)

(notably IEA 2014, NBS 2015 and BP 2015)


Introduction



Acidic Environment



Epoxy coated Rebars

Three years old chilled water retaining structure



Offshore BerthOffshore Berth



1

2 Definitions

3

Content

5

4



Definitions:sustainability

The most commonly accepted definition of sustainable development is:

"development that meets the needs of the present without compromising the ability of future generations to meet their own needs”

Sustainability objectives for infrastructure projects are best accomplished by ensuring:

• durable structures

• with long service life and minimal maintenance input. (long lasting)

• conserve natural resources and minimize waste (be an efficient, minimalist design, avoiding extravagant architectural statements)

• minimize material consumption over the whole of life.

• lowest whole-of-life economic cost (e.g. maintenance cost).

• disaster Resistant (earthquake, extreme wind, blast, etc.)



Definitions:Sustainability

Stages considered

when estimating

environmental

impact



Definitions:Durability

is defined as the design of a structure or facility to meet the design life requirement

– by material selection,

– degradation management,

– monitoring,

– inspection and maintenance



the period of time after the date of practical completion during which the item is expected to operate within its specified design parameters without replacement, refurbishment or major maintenance [Fagerlund, Göran: Service Life of Structures 1979].

Concrete structures shall be designed, constructed and operated in such a way that, under the expected environmental influences,

they maintain their safety, serviceability and acceptable appearance during an explicit or implicit period of time without

requiring unforeseen high costs for maintenance and repair

Definitions:Design Life

Today many owners require service lives of 80, 100

or even 200 or 300 years for important concrete

structures



Indicative Values for Design Service Life

Design

Service

Life, yrs

Examples

10 Temporary Structures (Structures or parts of

structures that can be dismantled with a view to

being reused are not to be considered temporary)

10 – 25 Replaceable structure parts, e.g., gantry girders,

bearings, metal roofs, etc.

15 – 30 Agricultural and similar structures

50 Buildings and other common structures

100 + Monumental buildings, bridges, and other civil

engineering structures

CEN Eurocode 0: basis of design, EN 1990



Design Life Examples

the Gateway Bridge Arterial crossing the Brisbane River in Queensland,

Australia 300 years design/service life

Opened for traffic 2010

A Joint Venture between Leighton Contractors and Abigroup Contractors



Southern Seawater Desalination Plant in Western Australia (Southern

Seawater Alliance - WorleyParsons)

100 years design /service life

Capacity 300 ML/d





Burj Khalifa Towers

100 year design life

Sheik Zayed Bridge – Abu Dhabi UAE



http://www.google.com.sa/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&docid=FqqFtd71EHVcnM&tbnid=RZsweK4xU0WJlM:&ved=0CAUQjRw&url=http://www.archello.com/en/project/sheikh-zayed-bridge-lighting-abu-dhabi-complete&ei=NBqcUrTmCtPaoAT1yYJI&psig=AFQjCNH8aPdKHolgMEH8_SZ3Ynqm4Vv80w&ust=1386048359276959



1

2

3

Content

5

4Provisions to enhance sustainability through durability

of concrete structures



Important notes

• the current emphasis on high strength and very high strength, and the design philosophy of Durability through Strength for concrete materials and concrete structures is fundamentally flawed. It is this misleading concept and vision that is primarily responsible for the lack of durable performance of concrete in real life environments.

• To change this scenario, current practices advocates that concrete materials must be manufactured for durability and not for strength.

• this concept of Strength through Durability can be achieved through careful design of the cement matrix and its microstructure

How concrete can be made more sustainable



1. Concrete specification shall be performance-based to achieve the durability requirements for a specific project. Prescription to Performance (P2P)



SAES-Q-001 “Criteria for Design and Construction of Concrete Structures”


SAES-Q-001 “Criteria for Design and Construction of Concrete Structures”


2. Interaction between durability design and execution.

3. Designer to adapt the design to the conditions under which the structure is to be constructed, operated and maintained.

4. Provision of electrical continuity for reinforcement in more aggressive environments, to enable future cathodic protection installation if required.

Provisions to enhance durability of concrete structures




5. Well-graded aggregate can reduce

the amount of cement required and

the amount of water needed

Uniform size aggregate

Mixture of course and fine aggregate

Rounded aggregates give a more workable

mix. Angular aggregates make concrete

harder to place, work and compact, but can

make concrete stronger

well g

raded

aggreg

ates




PC PFA or GGBFS

or Volcanic AshCSF

Optimum

Packing

Concrete

Concept of particle packing using different sized

cementitious materials to minimize voids

Cem

ent P

article Pack

ing

6. particle packing: ternary Mix



7. The use of various good quality supplementary cementitious materials, such as PFA, GGBS, microsilica (MS); Volcanic Ash and metakaolin (MK) refines the pore structure of concrete, achieving less permeable and chemical resistant concrete.




8. The use of self-compacting concrete (SCC). SCC is a concrete mix — where the placing and compaction has minimal dependence on the available workmanship on site — that would improve the quality of the concrete in the final structure.




Case Study #1: Upgrade Sewage Treatment Plant @ Udhailiyah

Cement Type I 350 Kg 65%

Fly Ash Type F 150 Kg 30%

Silica Fume 25 Kg 5%

W/Cm 152 Ltr 0.30

Total Cem. Mat. 525 100%

Course aggr. 10 mm

Admixture Viscocrte (Sika)

Slump 650 mm

Flowability time 6 hours

Compressive strength 120 Mpa @ 56 daya

Supplier: Saudi Readymix Co.


Udhayilyiah Effluent Tanks 2010


Saudi Aramco: Company General UseFIRST SAUDI CONCRETE CONFERENCE May 2016


Case Study #2: Rebuild Molten Sulfur Pits at Saudi Aramco: - Operating Conditions

Sulfuric Acid and H2S

Saudi Aramco: Company General UsePlan View

150 oC

14 oC

50 oC

Operating ConditionsOperating Parameters



Slag (GGBFS) 150 Kg 65%


W/Cm 152 Ltr 0.34


Course aggr. 10/20 mm

Admixture

Slump 650 mm


Permeability ASTM C-1202 /

AASHTO T-277

370 – 650 Coulombs

Absorption BS 1881-122:2011 4 - 5%

Sau

di

Rea

dy

mix

Co

.


Case Study: Rebuild Molten Sulfur Pits at Saudi Aramco



9. Use of permeability-reducing admixtures (concrete waterproofing from within).

– The use of an admixture — characterized by hydrophobic and pore-blocking ingredients (HPI) — considerably improve concrete durability with respect to chloride-induced corrosion in concrete mixtures.

– The effectiveness of two typical commercially available permeability-reducing admixtures, one characterized by crystal growth and the other by an HPI, were recently studied. Experimental chloride concentrations of concrete specimens exposed to a simulated coastal environment were reported.

– The results were in favor of using HPI whereas the inclusion of a crystal growth admixture seemed to have almost no detectable effects.




Reduction in Water Uptake

Relative to "Control"

Everdure Caltite 92.4%

3CC 91.5%

"crystal-growth" 12.5%

Reduction in Chloride Penetration

(20 mm depth)

Salt Water Immersion & Drying Cycles

Everdure Caltite 100%

3CC 98.4%

"crystal-growth" 25.3

NSW Roads & Traffic Authority (RTA)

(Australia)





Groundwater Analysis:

sulphates @ 7,200 mg/Lt. chlorides @ 53,000 mg/Lt

Hot, tidal salt pans in South

Australia’s Port Pirie in 1962

PLAIN (OPC) CONCRETE @ 22 YEARS

Inspected

In 2012 the

Caltite

concrete still

in excellent

condition

CALTITE CONCRETE @ 52 YEARS



Strategic Sewage Disposal Scheme, Hong Kong (SSDS)

Caltite System concrete •Membrane – Free • No Coatings

required


Dubai Mall Aquarium


Case Study #3: KAUST CMOR Buildings (Laboratories)Waterproofing System


Seepage, between RC Wall & Base

foundation (inside part of basement wall)


Seepage,

along sump

pit wall and

inside sump


Additional waterproofing sheets and wall installed

Ground floor leaks and damage


SCC with binary mix and Caltite

Supplier: Saudi Readymix Co.


Fly Ash 150 Kg 30%


W/cm 152 Ltr 0.34


Course aggr. 10 mm

Admixture Caltite + Superplastesizer + Viscosity &

retarder

Slump 700 mm


Permeability ASTM C-1202 /

AASHTO T-277

370 – 450 Coulombs

Absorption BS 1881-122:2011 0.8 %

Compressive strength @ 56 days 82 MPa (11,900 psi)



Casting floor Slab

Plastic sheets


Wall Formwork


Challenges

Many Pipe PenetrationsUpside down shoring


10. Selection of greater cover to reinforcement in aggressive environments

– The spacer material shall have a good bond to the concrete and shall have similar hygro-thermal deformation characteristics as concrete.

• Plastic spacers have different temperature coefficients than concrete (a factor of about ten)

• Because of their lack of bond with concrete, plastic spacers should never be used for water retaining or any structure with durability requirements

• Fiber concrete spacers made by ISO approved manufacturers are considered by many to be the Rolls Royce of the industry

– they have better load bearing capacity.

– they have better bonding with in-situ concrete as they are made from the same material. Hairline cracks are discouraged.

– They are fire resistant and not attacked by Alkalies.

– they are more cost-effective.




How concrete can be made more sustainableat many a places, especially in bridges and jetties, corrosion was

initiated at the locations of plastic spacers provided

Reinforcement corrosion due to the use of plastic spacers.

Plastic Chair

ISO approved Fiber concrete spacers


http://www.google.com.sa/url?sa=i&source=images&cd=&cad=rja&docid=nv9IUhWdDe7P3M&tbnid=wMsg3GstQ-rJ0M:&ved=0CAgQjRwwAA&url=http://www.maxfrank.co.uk/uk/products/spacers/extruded-fibre-reinforced-concrete-spacers.php&ei=K-CaUrC9JNfaoASu6oHADg&psig=AFQjCNF0D5vlUL3A6inOg3K8JMG_eeWCWQ&ust=1385968043637553

http://www.google.com.sa/url?sa=i&source=images&cd=&cad=rja&docid=nv9IUhWdDe7P3M&tbnid=wMsg3GstQ-rJ0M:&ved=0CAgQjRwwAA&url=http://www.maxfrank.co.uk/uk/products/spacers/extruded-fibre-reinforced-concrete-spacers.php&ei=K-CaUrC9JNfaoASu6oHADg&psig=AFQjCNF0D5vlUL3A6inOg3K8JMG_eeWCWQ&ust=1385968043637553


Plastic Chairs in Sulfur pit

melted after operation


11. Good detailing to enable compaction of concrete, along with good vibration and subsequent curing during construction, to ensure a dense layer of cover concrete.




Examples of poor specifications and construction Practices

Closely spaced

reinforcements that does not

allow concrete course

aggregates to pass through

Improper

compaction or

low slump

concrete



1

2

3

Content

5

4

Conclusions



• Durability is the key to sustainability.

• If the useful life of a structure can be extended by using concrete, that's a huge gain for sustainability.

• Performance based specifications are the basis for durable structures and the direction for the next era.

• Developments in concrete technology will continue to improve the industry's ability to respond.

• Durability plan is vitally important before starting any design and execution.

• A new design paradigm is needed for the design and execution of concrete structures. This is a precondition for concrete structures to increase competitiveness and thus remain the solid and reliable foundation for future societal prosperity.

Conclusions



Thank youAny Questions?



1

3 Durability Plan and Sustainability

2

5

4

Content

6



To achieve a sustainable structure, a durability plan prepared by specialist independent durability consultant is extremely important.

Durability planning process involves four main stages:

– environmental exposure assessment

– determination of the likely modes and rates of degradation

– selection of suitable materials for construction

– operation and maintenance requirements for the design life

Durability Plan and Sustainability



Fly ashSlag

cement

Silica

fume

Natural pozzolans

Class F Class CCalcined

shale

Calcined

clayMetakaolin

Water demand

Workability

Bleeding and

segregation

Impact of SCM characteristics on the fresh properties of concrete

Increases

Decreases

No impact

May increase

decrease

KEY

Reproduced from PCA – Design and control of concrete mixtures - 2011



Fly ashSlag

cement

Silica

fume

Natural pozzolans

Class F Class CCalcined

shale

Calcined

clayMetakaolin

Early age strength

Long term

strength gain

Abrasion

resistance

Drying shrinkage

and creep

Permeability and

absorption

Increases

Decreases

No impact

May increase

decrease

KEY

Impact of SCM characteristics on the Hardened properties of concrete



Examples of poor specifications and construction Practices

Closely spaced

reinforcements that does not

allow concrete course

aggregates to pass through

Improper

compaction or

low slump

concrete




Burj Khalifa Towers


Sheik Zayed Bridge – Abu Dhabi UAE






Dubai Mall AquariumWaterproofing admixture used for Commercial, Marine, Pools &

Tanks



Wrong waterproofing

installation


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Strategies to achieve sustainable and Durable Concrete ...saudiconcreteconference.com/pdfs/Dr. Emad Abu Aisheh -Stratrgies to... · Strategies to achieve sustainable and Durable Concrete